Think I have bacterial vaginosis. Having lower abdominal pain on left side. I douched with water and peroxide.was that OK? What should I do?

There are so many causes of abdominal pain, even lower left, that it would be presumptuous to try to say here.
Ovarian cyst, constipation or gas, diverticulitis, fibroids, muscle sprain, pinched nerve (I still have pain there from sacral nerve pain, which wraps around to the abdomen from the sacro-iliac), kidney stone in ureter, and so on - so I would just plain go get an ultrasound.
I don't think peroxide will harm you but personally prefer to stay away from douches, mouthwash, and anti-bacterial soaps.